Interference is a difficult problem in wireless communications. For instance, the capacity region of two-user Gaussian interference channels has been an open problem for over thirty years. Recently, there have been some studies regarding interference and interference alignment (IA) techniques.
In this regard, IA systems generally function to reduce a dimension of aggregated interference by aligning interference from different transmitters into a lower dimension subspace at each receiver, however, conventional systems experience real-world challenges and have not been feasible for a variety of reasons. The above-described contextual background regarding IA techniques is merely intended to provide a general overview of current technologies, and is not intended to be exhaustive.